public function testSample()
{
$list = ['a', 'b', 'c', 'd', 'e'];
$this->assertTrue(isList(sample($list, 3)));
$iterator = new \ArrayIterator($list);
$this->assertTrue(isList(sample($iterator, 3)));
foreach (sample($iterator, 3) as $item) {
$this->assertTrue(in_array($item, $list));
}
$sample = sample($list, 3, true);
foreach ($sample as $k => $element) {
$this->assertTrue($list[$k] === $element);
}
$this->assertEquals([], sample(['a', 'b', 'c'], 0));
$appearances = array_fill_keys($list, 0);
for ($i = 0; $i < 50000; ++$i) {
$sample = sample($list, 3);
foreach ($sample as $item) {
++$appearances[$item];
}
}
foreach ($appearances as $item => $rate) {
$this->assertEquals(30000, $rate, '', 500);
}
}
public function testIsList()
{
$this->assertFalse(isList(1));
$this->assertFalse(isList(array(1 => 'a')));
$this->assertFalse(isList(array(0 => 'a', 2 => 'c')));
$this->assertFalse(isList(new \StdClass()));
$this->assertTrue(isList([]));
$this->assertTrue(isList([1]));
$this->assertTrue(isList([1, 2, 3]));
$this->assertTrue(isList([10, 11, 13]));
}
/**
* Returns two lists, one containing values for which your predicate returned true until the predicate returned
* false, and the other containing all the elements that left
*
* @param callable $predicate
* @param array|\Traversable $sequence
* @return array
*/
function span(callable $predicate, $sequence)
{
args\expects(args\traversable, $sequence);
$isList = ds\isList($sequence);
$result = [[], []];
$listIndex = 0;
foreach ($sequence as $k => $v) {
if (!$predicate($v)) {
$listIndex = 1;
}
if ($isList) {
$result[$listIndex][] = $v;
} else {
$result[$listIndex][$k] = $v;
}
}
return $result;
}
/**
* Moves list element to another position
*
* @param array $list
* @param int $from
* @param int $to
* @return array
*/
function moveElement(array $list, $from, $to)
{
args\expects(args\int, $from);
args\expects(args\int, $to, 3);
if (!ds\isList($list)) {
throw new \InvalidArgumentException('First argument should be a list');
}
if (!isset($list[$from]) || !isset($list[$to])) {
throw new \InvalidArgumentException('From and to should be valid list keys');
}
if ($from === $to) {
return $list;
}
$moving = array_splice($list, $from, 1);
array_splice($list, $to, 0, $moving);
return $list;
}
